title: Lymph node ratio is a critical prognostic predictor in gastric cancer treated with S-1 chemotherapy.
abstract: BACKGROUND
  S-1 is an oral anticancer drug widely used in postoperative adjuvant therapy for patients in Japan with stage II/III gastric cancer. Candidates for more intense adjuvant treatments need to be identified, particularly among patients with stage III cancer.
  
  
  METHODS
  Univariate and multivariate analyses were conducted for patients with stage II/III gastric cancer who underwent surgery and received S-1 postoperatively between 2000 and 2010.
  
  
  RESULTS
  Factors indicating poor prognosis identified by univariate analysis include male sex (P = 0.022), age ≥67 years (P = 0.021), intestinal-type histology (P = 0.049), lymph node ratio ≥16.7 % (P < 0.0001), open surgery (P = 0.039), as well as the 13th JGCA stage (P < 0.0001) and the 14th JGCA/7th International Union Against Cancer (UICC) stage (P < 0.0001). Multivariate analysis revealed that lymph node ratio ≥16.7 % and intestinal-type histology were significant as predictors of prognosis, independent from the pathological stages. Based on these and other findings, stage IIIC cancer on the 14th JGCA/7th UICC stage system in combination with the lymph node ratio could identify patients with extremely high risk for recurrence
  
  
  CONCLUSIONS
  Our current findings suggest that lymph node ratio ≥16.7 % in combination with the new staging system could be a useful prognostic indicator in advanced gastric cancer. Because these high-risk patients cannot be identified preoperatively by any diagnostic tool, further improvement in postoperative adjuvant therapy is warranted.
authors.affiliation: Department of Surgery, Kitasato University School of Medicine, Sagamihara, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Ema
authors.forename: Keishi
authors.initials: K
authors.lastname: Yamashita
authors.forename: Shinich
authors.initials: S
authors.lastname: Sakuramoto
authors.forename: Guoqin
authors.initials: G
authors.lastname: Wang
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Mieno
authors.forename: Masayuki
authors.initials: M
authors.lastname: Nemoto
authors.forename: Tomotaka
authors.initials: T
authors.lastname: Shibata
authors.forename: Natsuya
authors.initials: N
authors.lastname: Katada
authors.forename: Shiro
authors.initials: S
authors.lastname: Kikuchi
authors.forename: Masahiko
authors.initials: M
authors.lastname: Watanabe
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D000368:Aged; D017024:Chemotherapy, Adjuvant; D004338:Drug Combinations; D005260:Female; D006801:Humans; D007564:Japan; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis / Q000473:pathology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009367:Neoplasm Staging; D010094:Oxonic Acid / Q000627:therapeutic use*; D011379:Prognosis; D013274:Stomach Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D005641:Tegafur / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D004338:Drug Combinations; C079198:S 1 (combination); D005641:Tegafur; D010094:Oxonic Acid